Max layer fan after 1st layer for best surface quality w/ short layer times

Isolate/insulate heater block from layer fan for consistent heating

More about HTPLA & heat treating:

HTPLA is a semi-crystalline grade of PLA optimized for heat treating (also known as annealing or crystallizing) for higher temperature use. Without heat treating, "as printed" amorphous PLA loses significant stiffness (and the thus the ability to retain form) as the material approaches it's relatively low glass transition temperature. Heat treating creates a more crystalline molecular structure for maintaining stiffness to near melting, thus extending the useful range of HTPLA, but also creates shrinkage. HTPLA parts should be scaled in slicer to compensate for shrinkage when heat treating.